Atomized spray dispenser with improved atomization

ABSTRACT

A dispenser for dispensing a measured dose of a spray of liquid in finely atomized form in compressed air. The dispenser body has a nozzle means opening out of the dispenser body, an air compressing piston-cylinder means mounted on the body and having a fixed member and a movable member movable relative to the fixed member through a compression stroke to compress the air. The body has a compressed air flow path therethrough from the air compressing piston-cylinder means to the nozzle means for conducting compressed air from the air compressing pistoncylinder means to the nozzle means, and a valve member in the body normally obturates the compressed air flow path. Actuating pin means operatively associated with the movable member of the air compressing piston-cylinder means and the valve member positively actuates the valve member to open the compressed air flow path near the end of the compression stroke only when the air compressing piston-cylinder means has compressed air to a predetermined pressure. A product supply means is provided on said dispenser body for dispensing a measured amount of a liquid product. The dispenser body has a product supply passage extending thereinto from the product supply means which intersects the compressed air flow path, so that the compressed air urges the liquid product toward the nozzle means. One or more shunt compressed air flow passages can also be provided extending from a point in the compressed air flow path upstream of the product supply passage to the nozzle means.

United States Patent Kleiner [451 Dec. 16, 1975 [54] ATOMIZED SPRAY DISPENSER WITH IMPROVED ATOMIZATION Primary ExaminerRobert B. Reeves Assistant Examiner-Joseph J. Rolla Attorney, Agent, or FirmWenderoth, Lind & Ponack 57 ABSTRACT A dispenser for dispensing a measured dose of a spray of liquid in finely atomized form in compressed air. The dispenser body has a nozzle means opening out of the dispenser body, an air compressing piston-cylinder means mounted on the body and having a fixed member and a movable member movable relative to the fixed member through a compression stroke to compress the air. The body has a compressed air flow path therethrough from the air compressing piston-cylinder means to the nozzle means for conducting compressed air from the air compressing piston-cylinder means to the nozzle means, and a valve member in the body normally obturates the compressed air flow path. Actuating pin means operatively associated with the movable member of the air compressing pistoncylinder means and the valve member positively actuates the valve member to open the compressed air flow path near the end of the compression stroke only when the air compressing piston-cylinder means has compressed air to a predetermined pressure. A product supply means is provided on said dispenser body for dispensing a measured amount of a liquid product. The dispenser body has a product supply passage extending thereinto from the product supply means which intersects the compressed air flow path, so that the compressed air urges the liquid product toward the nozzle means.

One or more shunt compressed air flow passages can also be provided extending from a point in the compressed air flow path upstream of the product supply passage to the nozzle means.

12 Claims, 7 Drawing Figures U.S. Patent Dec. 16, 1975 Sheet1of2 3,926,343

FIG]

ATOMIZED SPRAY DISPENSER WITH IMPROVED ATOMIZATION BACKGROUND OF THE INVENTION AND PRIOR ART The art of dispensing liquids in atomized form is rather highly developed. There has recently been developed a type of dispenser which has air compression means which is actuated to compress a predetermined amount of air to a predetermined pressure, and the dispenser releases the thus compressed air through an aspirating means which aspirates a liquid product to be dispensed from a supply thereof and ejects it from the dispenser as a spray of the atomozed liquid in compressed air. Such dispensers have a number of advantages, among which are the use of compressed air rather than the conventional aerosol propellants, such as Freon. Recent studies have revealed the possibility that Freon and other similar propellants may have certain toxic effects when inhaled by humans, and their use has been barred in products which are taken into the body in at least one country. Another advantage is that these dispeners inherently limit the amount of product which can be dispensed, since the amount of air compressed is limited, thus limiting the aspirating action of the aspirating means. Further, since air is compressed each time the dispenser is actuated, there is no supply of propellant which deteriorates or is exhausted.

However, the dispensers of this type which have been developed to date are all relatively complex, in that they require a number of parts which must be made separately 'and then assembled. Because of this, there has been a problem in gaining industry acceptance of such dispensers due to the cost resulting from the forming and assembly operations. Moreover, the atomization of the liquid product to be dispensed has not al ways been as good as is desired by the industry. It would therefore be a distinct advance in the art to find some simple way to improve such atomization without complicating the structure of the dispenser further than it is already complicated, i.e. without the necessity of adding parts or radically changing the existing parts.

OBJECTS AND BRIEF DESCRIPTION OF THE INVENTION It is an object of the present invention to provide a dispenser device which dispenses a dose of liquid to be dispensed in compressed air, in which the atomization of the liquid to be dispensed is improved, and in which the structure of the dispenser is kept relativly simple.

It is further object of the invention to provide a dispenser device of the type described in which the atomization of the liquid to be dispensed is improved without the necessity of adding parts to the dispenser or without the necessity of radically changing the parts of existing devices.

It is a further object of the invention to provide a dispenser device of the type described in which the structure thereof can be simplified without any significant loss of the atomization characteristics.

These objects are achieved by the provision of a dispenser according to the present invention, which dispenser has a dispenser body with a nozzle means opening thereoutof, and an air compressing piston-cylinder means mounted on said body and having a fixed member and a movable member movable relative to the fixed member through a compression stroke to compress the air. The body has a compressed air flow path therethrough from the air compressing piston-cylinder means to the nozzle means for conducting compressed air from the air compressing piston-cylinder means to the nozzle means. A valve member in the body normally obturates the compressed air flow path, and actuating pin means operatively associated with the movable member of the air compressing piston-cylinder means and said valve member positively actuates the valve member to open the compressed air flow path near the end of the compression stroke only when the air compressing piston-cylinder means has compressed air to a predetermined pressure. A product supply means forms part of said dispenser for dispensing a measured amount of a liquid product, said dispenser body having a product supply passage extending thereinto from said product supply means and intersecting said compressed air flow path. By this arrangement, the liquid is fed to the nozzle means by the action of compressed air which increases the velocity of the liquid, thus improving atomization, and in addition minimizes or ends clogging of the flow path for the liquid.

The nozzle means can be a Venturi nozzle, in which case additional flow passages for the compressed air can be provided leading to the central passage of the Venturi nozzle or to the throat thereof to increase atomizaion by causing aspiration of the liquid as well as pressure feed thereof, and by directly mixing the compressed air with the liquid fed by the compressed air.

BRIEF DESCRIPTION OF THE DILAVVINGS The invention will be further described in greater detail in the following specification, taken together with the accompanying drawings, in which:

FIG. 1 is a sectional elevation view of a first embodiment of the device for dispensing a measured dose of liquid according to the present invention, with the parts in the rest or non-dispensing positions;

FIG. 2 is a view similar to FIG. 1 with the parts in the dispensing positions;

FIGS. 3 7 are partial elevation views, partly in section, showing modified forms of the device of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION In all of the embodiments of the dispenser of the invention, air compressing piston cylinder means is provided on one end of a dispenser body 10, and in the embodiments disclosed comprise a cylinder 11 which extends downwardly from the body 10 and within which a piston 12 is slidably posititoned. Gasket 13 seals the piston in its movement into the cylinder 11. A return spring 14 within the cylinder 11 urges the piston 12 out of the cylinder 11. Opening out of the inner end of the cylinder 1 1 and into the body 10 is a recess 15. Within the recess 15 is a poppet valve member 17 which seats on a gasket 18 on a member 19 which is positioned in a larger recess 19a in the inner end of the cylinder 11 and which covers the recess 15, and the poppet valve member 17 seats on the gasket so that air cannot pass the poppet valve 17 from the cylinder to the recess. A valve return spring 20 in the recess holds the poppet valve on the gasket 18. An actuating pin 21 extends upwardly from the piston. At the inner end of the stroke of the piston 12, it engages the poppet valve 17 to lift it from the gasket 18 sufficiently far to pass compressed air into the recess.

A product supply means is provided on the dispenser which preferably supplies measured doses of a liquid product to be dispensed. This means supplies liquid to a product supply passage 33. One preferred supply means is shown in FIGS. 1 and 2 and comprises a piston-cylinder means generally indicated at 40 which in this embodiment has a piston 41 over which a cylinder 42 is slidable. A gasket 42a in the end of the piston 41 seals against the inside surface of the cylinder 42 as the cylinder slides along the piston. The piston 41 is made up of an outer shell 43 within which is positioned an inner body 44. The end of the shell 43 has an aperture 43a therein and on the inside of the shell between the bottom thereof and the end of the inner body 44 is a first annular sealing gasket 45. The inner body 44 has a larger diameter recess 44a in the end toward the bottom of the shell, and has a smaller diameter bore 44b extending from the inner end of the recess 44a to the end of the piston which is within the cylinder 42.

Movably mounted within the recess 44a and bore 44b is a metering valve stem generally indicated at 46 which hasa solid stem portion within the recess 44a and a hollow stem portion 47 extending from the solid stem portion out through the first annular sealing gasket 45 and the aperture 43a in the bottom of the shell 43, the outside surface of the hollow stem portion 47 being in sealing relationship with the first annular sealing gasket 45. At the joint between the hollow stern portion 47 and the solid stem portion is a flange 48, which in the rest position of the stem, as shown in FIG. 1, rests on the first annular gasket 45. The cross-sectional shape of the solid stem portion is such that it will move freely into the bore 44b. Around the end of the bore 44b where it opens into the larger diameter recess 44a is a second annular sealing gasket 50 through which the solid portion of the stem can move in sealing relationship therewith when the stem 46 is raised. A spring 49 is positioned between the second annular sealing gasket 50 and the flange 48, and urges the flange toward the first annular sealing gasket 45.

In the hollow stem portion 47 is an aperture 47b which in the rest position of the device as shown in FIG. 1 is below or outside the bottom of the piston 41. In the dispensing position this aperture is within the larger diameter recess 44a.

It will be seen that the valve stem 46 and the inner body 44 with its larger diamatar recess 44a, the annular sealing gaskets 45 and 50, and the spring 49 form a simple metering stern which is known from the aerosol dispensing art and is shown in US. Pat. No. 2,721,010.

This product supply means is positioned in an upwardly open recess 51 in the body 10, the recess 51 having a cross-sectional shape complementary to the cross-sectional shape of the cylinder 42 of the measured dose dispenser and into which the cylinder 42 fits in slidable relationship. A further recess 52 is provided in the bottom of the recess 51 which has a cross-sectional shape complementary to the cross-sectional shape of the hollow stern portion 47 and which receives the hollow stem portion 47 in a substantially fluid tight fit with the end of the stem portion 47 in the bottom of the recess 52 and, with the parts of the rest or non-dispensing positions as seen in FIG. 1, with the lower end of the piston 41 spaced above the bottom of the recess 51. It will thus be seen that pressure exerted on the end of the cylinder 42 will force the piston downwardly into the recess 51 while the stem 46 is held in a fixed position relative to the dispenser body 10. This exerts pressure on the liquid L within the cylinder and within the smaller diameter bore 44b and the larger diameter recess 44a. The opposing forces move piston 41 down along the stem 46 against the action of the spring 49, first causing the second annular sealing gasket to move down around the upper end of the solid portion of the stem 46 and seal off the recess 44a from the smaller diameter bore 44b and the interior to the cylinder 42 thus trapping a metered quantity of liquid in recess 44a. Thereafter, further movement of the cylinder and piston causes the first annular sealing gasket 45 to move past the aperture 47b so that the aperture 47b opens into recess 44a.

It has been found that with this construction, when the aperture 47b is open to the recess 44a, the liquid which has been trapped in the recess 44a is ejected from the hollow stem portion 47 into product supply passage 33 in a squirt which has considerable force.

The nozzle means in the dispenser of the present invention opens laterally of the dispenser body'10, and in the embodiments of FIGS. 1 5 is a Venturi nozzle 25 positioned in a recess 26, the nozzle 25 having a reduced diameter part 27 which fits into a smaller diameter recess 28 extending into the body 10 from the recess 26. The outside of the larger diameter part of the nozzle 25 is shaped so that when it is seated in the recess 26 there is an annular chamber 29 left around the nozzle 25. Opening into the throat 30 of the nozzle 25 are two diametrally opposed supply ports 31 which open into the annular chamber 29. The throat 30 opens into a diverging portion 32.

The nozzle means in the embodiments of FIGS. 6 and 7 is a simple straight cylindrical passage 25a which opens into a diverging portion 32a so that liquid and compressed gas flowing in the passage 25a when they reach the diverging portion 32a will expand and the liquid will be atomized.

In the embodiments of FIGS. 1-4, a compressed air bore extends from the recess 15 which has a vertically extending portion 16a and a horizontal portion 16b which opens into the annular chamber 29. The recess 15 and the air bore comprise a compressed air flow path through the body. Product supply passage 33 opens into the horizontal portion 16b at substantially right angles thereto.

In addition there is at least one shunt compressed air flow passage extending through the body 10 to the nozzle means. In the embodiment of FIGS. 1 and 2, this shunt compressed air flow passage is a bore 35 extending between the upper end of the recess 15 and the inner end of the smaller diameter recess 28 and opening into the converging portion of the throat 30 of the Venturi nozzle 25.

In this embodiment, the compressed air flowing through the throat 30 of the Venturi nozzle 25 aspirates product from the annular chamber 29 and in turn from the horizontal portion 16b of the compressed air flow passage into which the product supply passage 33 opens. In addition, the compressed air from the recess 15 is supplied to exert positive pressure on the product supplied -into the compressed air flow bore 16a, 16b.

These simultaneous actions combine to give a fine liquid spray, and little or no residue remains in the nozzle 25 or the compressed air path and product flow passage.

In the embodiment of FIG. 3, there are two shunt compressed air flow passages, the passage 35 the same as in the embodiment of FIGS. 1 and 2 and a passage 36 which extends from the recess to the annular chamber 29, preferably generally diametrally opposite the point at which the portion 16b extends into the annular chamber 29. In addition to thecombined action produced in theembodiment of FIGS. 1 and 2, this embodiment introduces compressed air to the chamber 29 and through the ports 31 which imparts a shearing action to the mixed liquid and compressed air entering the system from the portion .16b.- This furtherr improves the atomization.

In the embodiment of FIG. 4, there is only a single shunt compressed air flow passage, the passage 36 extending to the annular chamber 29, the passage 35 being omitted. The aspirating action of the'throat 30 of the Venturi nozzle is no longer produced, but the shearing action of the compressed air entering directly into the annular chamber 29 and the ports-31 greatly enhances atomization.

In the embodiment of FIG. 5, the compressed air flow bore 16a, 16b extends past the product supply passage 33 and then directlyinto the recess 28 and opens into the throat 30 of the Venturi nozzle 25. In addition, a single compressed air shunt flow passage 36 is provided from-the recess to, the annular chamber 29. In this embodiment, atomization is enhanced by the action of the compressed air entering the stream of mixed gas and liquid in the throat 30 through the lateral ports 31 and exerting a shearing action on the stream.-

In the embodiments of FIGS. 6* and 7, the Venturi nozzle is replaced with a simple diverging passage 25a, 32a. In the simplest form of the invention, the compressed air flow bore is comprised of the vertically extending portion 16a and the horizontally extending portion 161), into which the product supply passage 33 opens, and which in turn becomes the passage 25a of the nozzle means. In this embodiment, the compressed air is caused to flow in behind the liquid product, and the air combines with the liquid, the velocity is increased, and the mixture blows out of the nozzle means with the liquid emerging as a fine spray.

The embodiment of FIG. 7 is similar to that of FIG. 6 except that there is added a single compressed air shunt flow passage 35a which extends from the recess 15 into the passage 25a between the opening of the product flow passage 33 into the portion 16b and the point where the passage 25a diverges at 320. This compressed air shears the stream of mixed liquid and gas and enhances the atomization when the stream escapes from the unit as a fine spray.

It will be seen that for the embodiments of FIGS. 1 5, while the atomization has been substantially improved, the dispenser really has no more parts than do the similar dispensers disclosed in prior applications and patents of the present inventor. All that has been necessary is to rearrange the compressed air flow path and provide one or more compressed air shunt flow passages. This can be done by a simple drilling operation or by slightly changing the mold where the dispenser body is made of plastic. Improved results have therefore been acheived with only a minor modifica- 6 tion of the dispenser body 10, which can be done at a very small increase in cost.

On the other hand, for the embodiments of FIGS. 6 and 7, the rearrangement of the compressed air flow paths has improved the atomization sufficiently so that for certain uses the Venturi nozzle, a more or less precision molded part, can be omitted, with consequent reduction in the cost of manufacturing and assembling the dispenser.

Many changes will be obvious to those skilled in the art which will not depart from the spirit of the present invention; For example, a cylinder is shown as slidable over the piston in the measured dose dispenser. A simple redesign of these parts would make possible the movement of a piston into a cylinder. The same is true of the air compressing piston-cylinder means. Redesign could make possible the sliding of a cylinder over a fixed piston. Other product dispensing means could be used and such means could be located at a different position on the dispensing body.

Itis thought that the invention and its advantages will be understood from the foregoing description and it is apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing its material advantages, the forms hereinbefore described and illustrated in the drawings being merely preferred embodiments thereof.

What is claimed is:

1. A dispenser for dispensing a measured dose of a spray of liquid in finely atomized form in compressed air, comprising a dispenser body having a nozzle means opening out of said dispenser body and having a through passage ending in an outwardly diverging portion, an air compressing piston-cylinder means mounted on saidbody and having a fixed member and a movable member movable relative to the fixed member through a compression stroke to compress the air, the body having a compressed air flow path therethrough from the air compressing piston-cylinder means to the nozzle means for conducting compressed air from the air compressing piston-cylinder means to the nozzle means, a valve member in the body normally obturating the compressed air flow path, actuating pin means operatively associated with the movable member of the air compressing piston-cylinder means and said valve member for positively actuating the valve member to open the compressed air flow path near the end of the compression stroke when the air compressing piston-cylinder means has compressed air to a predetermined pressure, a liquid product supply means on said dispenser body including means for mechanically pressurizing the liquid product and for dispensing a measured amount of a liquid product under pressure, said dispenser body having a product supply passage extending thereinto from said product supply means and intersecting said compressed air flow path upstream of said nozzle means. 1

2. A dispenser as claimed in claim 1 in which said dispenser body further has at least one shunt compressed air flow passage extending from a point in said compressed air flow path upstream of said product supply passage to said nozzle means.

3. A dispenser as claimed in claim 2 in which said nozzle means is a Venturi nozzle having a throat therethrough and lateral supply ports opening into the throat, said dispenser body having an annular chamber around said Venturi nozzle into which the supply ports 7 open, and said compressed air flow path extending into said annular chamber.

4. A dispenser as claimed in claim 3 in which there is a single shunt compressed air flow path opening into said throat.

5. A dispenser as claimed in claim 3 in which there are two shunt compressed air flow passages, one opening into said throat and the other opening into said annular chamber at a point generally diametrally opposite the point at which said compressed air flow path extends into said annular chamber.

6. A dispenser as claimed in claim 3 in which there is a single shunt compressed air flow passage opening into said annular chamber.

7. A dispenser as claimed in claimed 6 in which said shunt compressed air flow path opens into said annular chamber at a point generally diametrally opposite the point at which said compressed air flow path extends into said annular chamber.

8. A dispenser a claimed in claim 2 in which said nozzle means is a Venturi nozzle having a throat therethrough and lateral supply ports opening into the throat, said dispenser body having an annular chamber around said Venturi nozzle into which the supply ports open, and said compressed air flow path extending into said throat.

9. A dispenser as claimed in claim 8 in which there is a single shunt compressed air flow path opening into said annular chamber.

10. A dispenser as claimed in claim 1 in which said nozzle means has a straight passage ending in an outwardly diverging portion, and said compressed air flow path extends into said straight passage.

11. A dispenser as claimed in claim 1 in which said product supply means comprises means for dispensing the measured amount of liquid product as a squirt of liquid under pressure.

12. A dispenser for dispensing a measured dose of-a spray of liquid in finely atomized form in compressed air, comprising a dispenser body having a nozzle means opening out of said dispenser body and having a straight passage ending in an outwardly diverging portion, an air compressing piston-cylinder means mounted on said body and having a fixed member and a movable member movable relative to the fixed member through a compression stroke to compress the air, the body having a compressed air flow path therethrough from the air compressing piston-cylinder means and opening into the straight passage of the nozzle means for conducting compressed air from the air compressing piston-cylinder means to the nozzle means, a valve member in the body normally obturating the compressed air flow path, actuating pin means operatively associated with the movable member of the air compressing piston-cylinder means and said valve member for positively actuating the valve member to open the compressed air flow path near the end of the compression stroke when the air compressing pistoncylinder means has compressed air to a predetermined pressure, a liquid product supply means on said dispenser body including means for mechanically pressurizing the liquid product and for dispensing a measured amount of a liquid product under pressure, said dispenser body having a product supply passage extending thereinto from said product supply means and intersecting said compressed air flow path upstream of said nozzle means, and said dispenser body further having a shunt compressed air flow passage extending, from a point in said compressed air flow path upstream of said product suppply passage, into said straight passage of said nozzle means between the supply passage and the diverging portion. 

1. A dispenser for dispensing a measured dose of a spray of liquid in finely atomized form in compressed air, comprising a dispenser body having a nozzle means opening out of said dispenser body and having a through passage ending in an outwardly diverging portion, an air compressing piston-cylinder means mounted on said body and having a fixed member and a movable member movable relative to the fixed member through a compression stroke to compress the air, the body having a compressed air flow path therethrough from the air compressing piston-cylinder means to the nozzle means for conducting compressed air from the air compressing piston-cylinder means to the nozzle means, a valve member in the body normally obturating the compressed air flow path, actuating pin means operatively associated with the movable member of the air compressing pistoncylinder means and said valve member for positively actuating the valve member to open the compressed air flow path near the end of the compression stroke when the air compressing piston-cylinder means has compressed air to a predetermined pressure, a liquid product supply means on said dispenser body including means for mechanically pressurizing the liquid product and for dispensing a measured amount of a liquid product under pressure, said dispenser body having a product supply passage extending thereinto from said product supply means and intersecting said compressed air flow path upstream of said nozzle means.
 2. A dispenser as claimed in claim 1 in which said dispenser body further has at least one shunt compressed air flow passage extending from a point in said compressed air flow path upstream of said product supply passage to said nozzle means.
 3. A dispenser as claimed in claim 2 in which said nozzle means is a Venturi nozzle having a throat therethrough and lateral supply ports opening into the throat, said dispenser body having an annular chamber around said Venturi nozzle into which the supply ports open, and said compressed air flow path extending into said annular chamber.
 4. A dispenser as claimed in claim 3 in which there is a single shunt compressed air flow path opening into said throat.
 5. A dispenser as claimed in claim 3 in which there are two shunt compressed air flow passages, one opening into said throat and the other opening into said annular chamber at a point generally diametrally opposite the point at which said compressed air flow path extends into said annular chamber.
 6. A dispenser as claimed in claim 3 in which there is a single shunt compressed air flow passage opening into said annular chamber.
 7. A dispenser as claimed in claimed 6 in which said shunt compressed air flow path opens into said annular chamber at a point generally diametrally opposite the point at which said compressed air flow path extends into said annular chamber.
 8. A dispenser a claimed in claim 2 in which said nozzle means is a Venturi nozzle having a throat therethrough and lateral supply ports opening into the throat, said dispenser body having an annular chamber around said Venturi nozzle into which the supply ports open, and said compressed air flow path extending into said throat.
 9. A dispenser as claimed in claim 8 in which there is a single shunt compressed air flow path opening into said annular chamber.
 10. A dispenser as claimed in claim 1 in which said nozzle means has a straight passage ending in an outwardly diverging portion, and said compressed air flow path extends into said straight passage.
 11. A dispenser as claimed in claim 1 in which said product supply means comprises means for dispensing the measured amount of liquid product as a squirt of liquid under pressure.
 12. A dispenser for dispensing a measured dose of a spray of liquid in finely atomized form in compressed air, comprising a dispenser body having a nozzle means opening out of said dispenser body and having a straight passage ending in an outwardly diverging portion, an air compressing piston-cylinder means mounted on said body and having a fixed member and a movable member movable relative to the fixed member through a compression stroke to compress the air, the body having a compressed air flow path therethrough from the air compressing piston-cylinder means and opening into the straight passage of the nozzle means for conducting compressed air from the air compressing piston-cylinder means to the nozzle means, a valve member in the body normally obturating the compressed air flow path, actuating pin means operatively associated with the movable member of the air compressing piston-cylinder means and said valve member for positively actuating the valve member to open the compressed air flow path near the end of the compression stroke when the air compressing piston-cylinder means has compressed air to a predetermined pressure, a liquid product supply means on said dispenser body including means for mechanically pressurizing the liquid product and for dispensing a measured amount of a liquid product under pressure, said dispenser body having a product supply passage extending thereinto from said product supply means and intersecting said compressed air flow path upstream of said nozzle means, and said dispenser body further having a shunt compressed air flow passage extending, from a point in said compressed air flow path upstream of said product suppply passage, into said straight passage of said nozzle means between the supply passage and the diverging portion. 